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Fisher Receiver?

Seems like this would probably use cathode bias rather than fixed bias as the tubes are smaller...locate the cathodes of the 6HU8's and see if there is a resistor from the cathodes to ground. If so, measure the cathode voltage, should be between 8-12 volts or so. If it uses the cathode resistor and cathode voltage is zero, the cathode bypass cap likely is shorted...you can remove the cap for testing, you will just get less gain out of the tubes.
Would be good to replace all electrolytics too...if you don't see a selenium, this likely uses silicon diodes for rectifiers and probably a voltage doubler supply...it would be good to replace those diodes with modern ones with at least 1000 piv...old silicon diodes can short.
 
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I kept looking and did find 2 RCA (?) branded rectifiers (small axial, silver with the diode symbol stamped on them) so I'll need a source and parts matching for those part numbers once I get the magnifying glass out to read them. Each is inline to one of 2 large cardboard caps (most certainly to be replaced). Bid high and won a set of ELL80s on the 'bay just in case I crapped mine out of service last weekend.
 
Chad Hauris said:
A 1000 PIV, 1 amp silicon diode ought to work to replace these.
I think the generic type number is 1N4007.
Click to expand...


Yup that be the basic replacements. If you want to go all out install some Fairchild Stealth diodes but I think you would be hard pressed to hear the difference over the basic 1N4007
 
It appears to have also been called "the Fisher" Philharmonic. One up for auction now and it is identical (with the exception of the faceplate material) to mine. This version certainly has "shag me baby" written all over it! :banana:
 
God how I hate waiting for my parts to arrive. :beatnik: It's bad enough that I have taken to "polishing" the chassis. Can't even build a cabinet for the piece until I know she's running okay. I did find a couple of old Popular Mechanics "how to books" at the thrifty and I am edumacatin' myself on state-of the-art tube radio troubleshooting circa 1961. Now let's see....voltage flows from negative to positive and is measured in amperes.....
 
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